Comparison of properties of polymer organic solar cells prepared using highly conductive modified PEDOT:PSS films by spin- and spray-coating methods

Abstract

Bulk heterojunction (BHJ) solar cells have made great progress over the past decade and consequently are now attracting extensive academic and commercial interest because of their potential advantages: lightweight, flexible, low cost, and high-throughput production. Polymer conductivity is a key factor for improving the performance of electronic and photonic devices. Poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) is promising for use as a next-generation transparent electrode of optoelectronic devices. In this research, we compare the effect of nanomorphology on conductivity, and power conversion efficiency of polymer organic solar cells prepared by the spin-and spray-coating methods.To improve the conductivity of spray-deposited PEDOT:PSS, we modified the PEDOT:PSS films by simple UV irradiation and by UV irradiation with treatment using various solvents such as methanol, ethanol, acetone, acetonitrile, hydrochloric acid, and sulfuric acid to form a hole transport layer (HTL). The active layer of PTB7:PC 70 BM is spray-coated on top of the PEDOT:PSS layer. The films were examined by optical spectroscopy, micro-Raman spectroscopy, and conductivity measurements. The surface morphology of the deposited films was examined by atomic force microscopy (AFM). The current density-voltage (J-V) characteristics were measured under illumination with simulated solar light at 100 mW/cm 2 (AM 1.5G) using an oriel 1000 W solar simulator. The obtained results are expected to have a considerable impact and suggest a bright future for organic polymer solar cells.

Effect of incorporation of ethylene glycol into PEDOT:PSS on electron phonon coupling and conductivity

“…PEDOT:PSS represents the next-generation of electrodes because of its high transparency in the visible range, its solution processability, its high work function, and its significant mechanical flexibility. [1][2][3][4][5][6][7][8][9][10][11][12][13][14] With the widespread use of PEDOT:PSS, a number of studies are attempting to determine and improve its properties. A common method that is used to improve the properties of PEDOT:PSS is a chemical treatment that involves the addition of co-solvents, which results in considerable improvement to the polymer's conductivity.…”

Spray coating methods for polymer solar cells fabrication: A review

“…For fully spray coated devices, depositing a PEDOT:PSS buffer layer or top-electrode from aqueous solution on a non-polar active layer in inverted PSC is commonly considered a very challenging task [27,56]. This is due to the wettability problem of highly hydrophilic PEDOT:PSS aqueous solution into the P3HT:PCBM film, resulting in very poor device performance [15,27]. For fully spray coated inverted devices, a very high RMS roughness, as shown in Fig.…”

“…Blade coating [5,6], spin coating [7][8][9], spray coating [10][11][12][13][14][15], dip coating [1], screen printing [16], gravure printing [17], and ink-jet printing [18][19][20] are among the methods used to fabricate the PSC. Table 1 lists the previous researches on PSC prepared using different methods.…”

Performance evaluation of PTB7 : PC71BM based organic solar cells fabricated by spray coating method using chlorine free solvent

“…This often results in no uniform phase segregation due to large fullerene / polymer rich grains in the cast films, reveals limiting the device performance 32 This critical issue was solved by adding the more suitable additive with solvent and it enhances the fullerene solubility and exhibit enhanced device performance. 13,[34][35][36][37][38][39][40][41][42][43] Therefore, development of polymer solar cell using chlorine-free solvents by spray coating is capable of delivering large-area, uniform films with small amounts of material, which is having the compatibility for roll-to-roll fabrication is crucial. 24,27 However, spray-coating techniques are being explored for large-area, uniform thin film and wastage of material is low compare with other method.…”